scholarly journals The Function of the Hypothalamic–Pituitary–Adrenal Axis During Experimental Autoimmune Encephalomyelitis: Involvement of Oxidative Stress Mediators

2021 ◽  
Vol 15 ◽  
Author(s):  
Svetlana Trifunovic ◽  
Ivana Stevanovic ◽  
Ana Milosevic ◽  
Natasa Ristic ◽  
Marija Janjic ◽  
...  

Multiple sclerosis (MS) is an inflammatory, demyelinating disease with an unknown origin. Previous studies showed the involvement of the hypothalamic–pituitary–adrenal (HPA) axis to susceptibility to autoimmune diseases, including MS, and its best-characterized animal model, experimental autoimmune encephalomyelitis (EAE). During MS/EAE, innate immune cells are activated and release cytokines and other inflammatory mediators, leading to a vicious cycle of inflammation. In response to inflammation, the activated HPA axis modulates immune responses via glucocorticoid activity. Because the mechanisms involving oxidative stress to the HPA axis are relatively unrevealed, in this study, we investigate the inflammatory and oxidative stress status of HPA axis during EAE. Our results reveal an upregulation of Pomc gene expression, followed by POMC and ACTH protein increase at the peak of the EAE in the pituitary. Also, prostaglandins are well-known contributors of HPA axis activation, which increases during EAE at the periphery. The upregulated Tnf expression in the pituitary during the peak of EAE occurred. This leads to the activation of oxidative pathways, followed by upregulation of inducible NO synthase expression. The reactive oxidant/nitrosative species (ROS/RNS), such as superoxide anion and NO, increase their levels at the onset and peak of the disease in the pituitary and adrenal glands, returning to control levels at the end of EAE. The corticotrophs in the pituitary increased in number and volume at the peak of EAE that coincides with high lipid peroxidation levels. The expression of MC2R in the adrenal glands increases at the peak of EAE, where strong induction of superoxide anion and malondialdehyde (MDA), reduced total glutathione (GSH) content, and catalase activity occurred at the peak and end of EAE compared with controls. The results obtained from this study may help in understanding the mechanisms and possible pharmacological modulation in MS and demonstrate an effect of oxidative stress exposure in the HPA activation during the course of EAE.

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Ani Grigorian ◽  
Michael Demetriou

Multiple sclerosis (MS) is an inflammatory demyelinating and neurodegenerative disease initiated by autoreactive T cells. Mgat5, a gene in the Asn (N-) linked protein glycosylation pathway, associates with MS severity and negatively regulates experimental autoimmune encephalomyelitis (EAE) and spontaneous inflammatory demyelination in mice. N-glycan branching by Mgat5 regulates interaction of surface glycoproteins with galectins, forming a molecular lattice that differentially controls the concentration of surface glycoproteins. T-cell receptor signaling, T-cell proliferation, TH1 differentiation, and CTLA-4 endocytosis are inhibited by Mgat5 branching. Non-T cells also contribute to MS pathogenesis and express abundant Mgat5 branched N-glycans. Here we explore whether Mgat5 deficiency in myelin-reactive T cells is sufficient to promote demyelinating disease. Adoptive transfer of myelin-reactive Mgat5−/− T cells into Mgat5+/+ versus Mgat5−/− recipients revealed more severe EAE in the latter, suggesting that Mgat5 branching deficiency in recipient naive T cells and/or non-T cells contribute to disease pathogenesis.


2021 ◽  
Vol 31 (Supplement_2) ◽  
Author(s):  
Maiara Carolina Perussolo ◽  
Bassam Felipe Mogharbel ◽  
Lucia de Noronha ◽  
Katherine Athayde Teixeira de Carvalho

Abstract Background Multiple sclerosis (MS) is an autoimmune disease of the central nervous system, characterized as an inflammatory demyelinating disease. It presents a diversity of neurologic signs and symptoms as well the incapacities. Since the need for advances in MS treatment, many studies are for new therapeutic technologies, mainly through using preclinical models as experimental autoimmune encephalomyelitis (EAE). This study aimed to observe and analyze the development in Lewis rats-induced model of EAE. Methods It was used 23 females of Rattus norvegicus, from 6 to 8 weeks, weighing around 170 g. Of 23 rats, 19 underwent EAE induction distributed in six groups to establish the evolution of clinical signs. B. pertussis toxin (PTX) doses were 200, 250, 300, 350–400 ng, and four animals as the control group. The animals had weight and scores analyzed daily, starting seven and ending 24 days after induction. Then, all animals were euthanized, and the brain and spinal cord were collected for histopathological analyses. Results The results showed that the dose of 250 ng of PTX induced de higher score and weight reduction. All groups who received the PTX demonstrated histopathological findings. Those characterized as leukocyte infiltration, activation of microglia and astrocytes, and demyelinated plaques in the brain. In the spinal cord, the loosening of the myelinated fibers was observed by increasing the axonal space in all tested doses of PTX. Conclusions EAE was not dose-dependent. Histopathological findings do not proportionally related to clinical signs, as in human patients with MS.


2018 ◽  
Vol 1 (5) ◽  
pp. e201800039 ◽  
Author(s):  
Lei Sun ◽  
Elphine Telles ◽  
Molly Karl ◽  
Fengdong Cheng ◽  
Noreen Luetteke ◽  
...  

Multiple sclerosis (MS) is a chronic, immune-mediated, demyelinating disease of the central nervous system (CNS). There is no known cure for MS, and currently available drugs for managing this disease are only effective early on and have many adverse side effects. Results from recent studies suggest that histone deacetylase (HDAC) inhibitors may be useful for the treatment of autoimmune and inflammatory diseases such as MS. However, the underlying mechanisms by which HDACs influence immune-mediated diseases such as MS are unclear. More importantly, the question of which specific HDAC(s) are suitable drug targets for the potential treatment of MS remains unanswered. Here, we investigate the functional role of HDAC11 in experimental autoimmune encephalomyelitis, a mouse model for MS. Our results indicate that the loss of HDAC11 in KO mice significantly reduces clinical severity and demyelination of the spinal cord in the post-acute phase of experimental autoimmune encephalomyelitis. The absence of HDAC11 leads to reduced immune cell infiltration into the CNS and decreased monocytes and myeloid DCs in the chronic progressive phase of the disease. Mechanistically, HDAC11 controls the expression of the pro-inflammatory chemokine C–C motif ligand 2 (CCL2) gene by enabling the binding of PU.1 transcription factor to the CCL2 promoter. Our results reveal a novel pathophysiological function for HDAC11 in CNS demyelinating diseases, and warrant further investigations into the potential use of HDAC11-specific inhibitors for the treatment of chronic progressive MS.


2012 ◽  
Vol 64 (3) ◽  
pp. 843-850 ◽  
Author(s):  
Danijela Savic ◽  
Irena Lavrnja ◽  
Sanja Dacic ◽  
Ivana Bjelobaba ◽  
Nadezda Nedeljkovic ◽  
...  

Experimental autoimmune encephalomyelitis (EAE) is an animal model of multiple sclerosis (MS), a human inflammatory and demyelinating disease. Microglia and astrocytes are glial cells of the central nervous system (CNS) that play a dual role in MS and EAE pathology. The aim of this study was to examine the effect of combined treatment with two nucleoside analogues, ribavirin and tiazofurin, on microglia and astrocytes in actively induced EAE. Therapeutic treatment with a combination of these two nucleoside analogues reduced disease severity, mononuclear cell infiltration and demyelination. The obtained histological results indicate that ribavirin and tiazofurin changed activated microglia into an inactive type and attenuated astrocyte reactivity at the end of the treatment period. Since reduction of reactive microgliosis and astrogliosis correlated with EAE suppression, the present study also suggests that the obtained beneficial effect of ribavirin and tiazofurin could be a consequence of their action inside as well as outside the CNS.


Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 827
Author(s):  
Aline C. Giardini ◽  
Bianca G. Evangelista ◽  
Morena B. Sant’Anna ◽  
Barbara B. Martins ◽  
Carmen L. P. Lancellotti ◽  
...  

Multiple sclerosis (MS) is a demyelinating disease of inflammatory and autoimmune origin, which induces sensory and progressive motor impairments, including pain. Cells of the immune system actively participate in the pathogenesis and progression of MS by inducing neuroinflammation, tissue damage, and demyelination. Crotalphine (CRO), a structural analogue to a peptide firstly identified in Crotalus durissus terrificus snake venom, induces analgesia by endogenous opioid release and type 2 cannabinoid receptor (CB2) activation. Since CB2 activation downregulates neuroinflammation and ameliorates symptoms in mice models of MS, it was presently investigated whether CRO has a beneficial effect in the experimental autoimmune encephalomyelitis (EAE). CRO was administered on the 5th day after immunization, in a single dose, or five doses starting at the peak of disease. CRO partially reverted EAE-induced mechanical hyperalgesia and decreased the severity of the clinical signs. In addition, CRO decreases the inflammatory infiltrate and glial cells activation followed by TNF-α and IL-17 downregulation in the spinal cord. Peripherally, CRO recovers the EAE-induced impairment in myelin thickness in the sciatic nerve. Therefore, CRO interferes with central and peripheral neuroinflammation, opening perspectives to MS control.


1994 ◽  
Vol 77 (5) ◽  
pp. 2341-2347 ◽  
Author(s):  
C. Le Page ◽  
A. Ferry ◽  
M. Rieu

We examined whether physical exercise affected the development of an autoimmune response, experimental autoimmune encephalomyelitis (EAE), which is a demyelinating disease leading to paralysis. EAE was inducted on day 0, in rats of both sexes, by injecting them with spinal cord tissue in adjuvant. From days 1 to 10 after injection, exercised rats (n = 55) ran on a treadmill (60–120 min/day) before the onset of the paralytic disease. Clinical signs of the disease (ataxia, paralysis, and body mass loss) were examined in exercised and control rats (n = 54). Three types of EAE were induced: monophasic, acute, and chronic relapsing (CR)-EAE (3 bouts of disease, CR-EAE 1, 2, and 3, separated by remissions). Exercise significantly delayed the onset of CR-EAE 1 (P = 0.001) and the 1st day of maximum severity of CR-EAE 1 (P = 0.001) and CR-EAE 2 (P = 0.002). Moreover, the duration of CR-EAE 1 was significantly decreased in exercised rats compared with control rats (P = 0.004). The peak severity of the different types of EAE was not modified by exercise. The present study indicates that endurance exercise during the phase of induction of EAE diminished lightly only one type of EAE (CR-EAE) and therefore did not exacerbate the autoimmune disease.


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